The present invention relates to a device for supporting a tabular print head having a length sufficient to effect one-line printing on a chart passing between the print head and a platen upon which the head elastically impinges.
This type of print head assumes a configuration which is considerably elongate sideways, and it is therefore quite difficult to uniformly impinge the platen with the print head over its entire length, resulting in an often occurring phenomenon in which unevenness in density can be seen in the one-line printing. Under such circumstances, the applicants of the present invention proposed the invention disclosed in Japanese Patent Publication No. 64-11472. The arrangement is as follows. Fixed at a spacing to a rear surface of a tabular head substrate are a pair of mounting plates formed with crooks. A supporting shaft is provided with a pair of supporting levers each independently rotatable, which are in turn provided with erectly bent members spaced from the crooks of the mounting plates. Springs are interposed between the crooks and the erectly bent members to which screws for adjusting the height of the head substrate are spirally attached, penetrating the crooks. The adjusting screws serve to independently bilaterally adjust the level of the head substrate. The supporting levers are biased by spring forces to thereby thrust the head substrate against the platen disposed in front.
The construction of the prior art device described above involves the use of a good number of components such as the mounting plates, the height-adjusting screws, the springs wound on the screws and also the springs for thrusting the head substrate against the platen. This results in laborious assembly. In addition, the adjusting screws have to be rotated, resulting in a complicated adjustment.